From patchwork Mon Jun 20 08:10:26 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mika Kahola X-Patchwork-Id: 9186797 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B56C260756 for ; Mon, 20 Jun 2016 08:10:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9769424B5B for ; Mon, 20 Jun 2016 08:10:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8C11F25221; Mon, 20 Jun 2016 08:10:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 04FA824B5B for ; Mon, 20 Jun 2016 08:10:40 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 616266E427; Mon, 20 Jun 2016 08:10:38 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTP id D1ACE6E41C for ; Mon, 20 Jun 2016 08:10:36 +0000 (UTC) Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga102.fm.intel.com with ESMTP; 20 Jun 2016 01:10:36 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,497,1459839600"; d="scan'208";a="979458113" Received: from sorvi.fi.intel.com ([10.237.72.50]) by orsmga001.jf.intel.com with ESMTP; 20 Jun 2016 01:10:28 -0700 From: Mika Kahola To: intel-gfx@lists.freedesktop.org Date: Mon, 20 Jun 2016 11:10:26 +0300 Message-Id: <1466410226-19543-1-git-send-email-mika.kahola@intel.com> X-Mailer: git-send-email 1.9.1 Cc: stable@vger.kernel.org Subject: [Intel-gfx] [PATCH RESEND] drm/i915: Revert DisplayPort fast link training feature X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP It has been found out that in some HW combination the DisplayPort fast link training feature caused screen flickering. Let's revert this feature for now until we can ensure that the feature works for all platforms. This is a manual revert of commits 5fa836a9d859 ("drm/i915: DP link training optimization") and 4e96c97742f4 ("drm/i915: eDP link training optimization"). Fixes: 5fa836a9d859 ("drm/i915: DP link training optimization") Fixes: 4e96c97742f4 ("drm/i915: eDP link training optimization") Cc: # v4.2+ Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91393 Reviewed-by: Jani Nikula Signed-off-by: Mika Kahola --- drivers/gpu/drm/i915/intel_dp.c | 3 --- drivers/gpu/drm/i915/intel_dp_link_training.c | 26 ++------------------------ drivers/gpu/drm/i915/intel_drv.h | 2 -- 3 files changed, 2 insertions(+), 29 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index be08351..3cdea4d7a 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -4621,9 +4621,6 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd) intel_display_power_get(dev_priv, power_domain); if (long_hpd) { - /* indicate that we need to restart link training */ - intel_dp->train_set_valid = false; - intel_dp_long_pulse(intel_dp->attached_connector); if (intel_dp->is_mst) ret = IRQ_HANDLED; diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c index 0b8eefc..60fb39c 100644 --- a/drivers/gpu/drm/i915/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c @@ -85,8 +85,7 @@ static bool intel_dp_reset_link_train(struct intel_dp *intel_dp, uint8_t dp_train_pat) { - if (!intel_dp->train_set_valid) - memset(intel_dp->train_set, 0, sizeof(intel_dp->train_set)); + memset(intel_dp->train_set, 0, sizeof(intel_dp->train_set)); intel_dp_set_signal_levels(intel_dp); return intel_dp_set_link_train(intel_dp, dp_train_pat); } @@ -161,23 +160,6 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp) break; } - /* - * if we used previously trained voltage and pre-emphasis values - * and we don't get clock recovery, reset link training values - */ - if (intel_dp->train_set_valid) { - DRM_DEBUG_KMS("clock recovery not ok, reset"); - /* clear the flag as we are not reusing train set */ - intel_dp->train_set_valid = false; - if (!intel_dp_reset_link_train(intel_dp, - DP_TRAINING_PATTERN_1 | - DP_LINK_SCRAMBLING_DISABLE)) { - DRM_ERROR("failed to enable link training\n"); - return; - } - continue; - } - /* Check to see if we've tried the max voltage */ for (i = 0; i < intel_dp->lane_count; i++) if ((intel_dp->train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0) @@ -284,7 +266,6 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp) /* Make sure clock is still ok */ if (!drm_dp_clock_recovery_ok(link_status, intel_dp->lane_count)) { - intel_dp->train_set_valid = false; intel_dp_link_training_clock_recovery(intel_dp); intel_dp_set_link_train(intel_dp, training_pattern | @@ -301,7 +282,6 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp) /* Try 5 times, then try clock recovery if that fails */ if (tries > 5) { - intel_dp->train_set_valid = false; intel_dp_link_training_clock_recovery(intel_dp); intel_dp_set_link_train(intel_dp, training_pattern | @@ -322,10 +302,8 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp) intel_dp_set_idle_link_train(intel_dp); - if (channel_eq) { - intel_dp->train_set_valid = true; + if (channel_eq) DRM_DEBUG_KMS("Channel EQ done. DP Training successful\n"); - } } void intel_dp_stop_link_train(struct intel_dp *intel_dp) diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 0c1dc9b..9257f08 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -894,8 +894,6 @@ struct intel_dp { /* This is called before a link training is starterd */ void (*prepare_link_retrain)(struct intel_dp *intel_dp); - bool train_set_valid; - /* Displayport compliance testing */ unsigned long compliance_test_type; unsigned long compliance_test_data;